摘要
随着非线性电力电子器件的大量应用,电网存在频率为基频非整数倍的间谐波,其幅值远小于基波和谐波,并具有时变性,因此对它的检测要难于谐波。为此,采用dq变换和MUSIC算法相结合的方法进行间谐波频率检测,信号的幅度和相位由最小二乘法来估计。dq变换可以消除大幅度基波分量;基于矩阵特征分解的MUSIC算法可检测出短数据条件下的谐波和间谐波,适合短时平稳的间谐波检测,两者相结合可以有效检测出大幅度基波附近存在小幅度间谐波。仿真实验表明,噪声幅度和间谐波幅度相当时。
With the wide application of nonlinear power electronic devices the interharmonics which is the non- integer times of fundamental frequency exist in the power grid. Considering the low amplitude and characteristics of time-variability, the accurate interharmonic detection is more difficult than the harmonic detection. The dq transform and multiple signal classification （MUSIC） algorithm is used to detect the frequency of interharmonics in this paper, and the amplitude and phase of signal is estimated by the least squares method. The high base waveform can be eliminated by dq transform; MUSIC algorithm using the matrix eigen-decomposition method can detect the armonics and interharmonics on the basis of short data and is suitable for the short-time and steady interharmonic detection. The combination of both algorithms can effectively detect the low interharmonic around high base waveform. Simulation results show that the proposed algorithm is can effectively detect the low interharmonic around high base waveform in 4 periods data when the interharmonic amplitude is considerable with noise amplitude.
出处
《电力系统及其自动化学报》
CSCD
北大核心
2012年第5期83-87,共5页
Proceedings of the CSU-EPSA
关键词
电能质量
间谐波
dq变换
多信号分类法
power quality
interharmonic
dq transform
multiple signal classification （MUSIC） algorithm
